Wolf Singer
Wolf Singer argues that the binding problem, the question of how a brain integrating information across distributed cortical areas produces a unified conscious experience rather than a collection of independent representations, is solved by temporal synchrony. Specifically, by the co-ordinated firing of neurons across areas in the gamma-frequency range, approximately 30 to 80 Hz, with precision in the millisecond range. The cycle period of 40 Hz oscillations is 25 milliseconds, and Singer’s account implies that neurons contributing to the same conscious percept must synchronise their firing within that window.
This is a stronger temporal claim than most competing theories make. The Global Neuronal Workspace Theory of Dehaene and Changeux places the key event at around 300 ms after stimulus onset. IIT, as Koch and Tononi have developed it, makes no explicit temporal prediction at all: phi is a property of causal structure, not of oscillatory dynamics. Singer’s 25 ms window is the binding theory’s sharpest constraint on any physical architecture that might instantiate consciousness, and it is the constraint that places real limits on how physically distributed a conscious system can be: at 40 Hz, nodes separated by more than a few milliseconds of propagation delay cannot maintain the phase coherence the theory requires.
Christof Koch, in The Feeling of Life Itself (MIT Press, 2019), argued that gamma synchrony is neither necessary nor sufficient for consciousness, citing cases of conscious perception without gamma synchrony and oscillatory gamma activity without consciousness. That objection has not resolved the dispute: Singer’s group and others continue to find stimulus-dependent gamma coherence correlated with conscious access in human intracranial recordings. The disagreement is partly empirical and partly about what kind of correlation is relevant to identifying a neural mechanism rather than a neural correlate.
Known for. The temporal binding hypothesis, gamma-band synchrony as the mechanism for conscious feature integration
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Every researcher covered on this site is indexed in the directory of consciousness researchers, grouped by the position their published work defends. The positions themselves are set out in the index of consciousness theories.